1. Field of the Invention
The invention relates generally to automatic swimming pool cover systems, and, in particular to a system for sequentially supporting, opening and closing a pool-deck lid covering below-deck troughs housing with the operation of powered pool cover systems.
2. Description of the Prior Art
Swimming pools integrated with pool cover systems extending and retracting covers across the pool surface are safer, energy efficient, less expensive and easier to maintain. Pool covers also prevent heat and water loss through evaporation. It is also desirable to curtail other water losses from pools where water is scarce.
Water splashing over into below-deck troughs housing pool cover systems is primary source water loss from so equipped swimming pools. In particular, the bond beam topping the pool wall between the pool and trough housing are necessarily lower than the surrounding pool deck to allow retraction and extension of pool covers anchored by pool cover tracks secured in or along adjacent pool side walls. [See For example U.S. Pat. No. 5,913,613, Ragsdale; U.S. Pat. No. 6,446,276, Mathis; U.S. Pat. No. 6,496,990, Last; & U.S. Pat. No. 6,769,141, Epple et al.]
Below-deck troughs housing pool cover systems adjacent a sidewall of a swimming pool also present structural and design problems affecting access to the pool. In particular the housing troughs require pool deck lid structures that integrate with the deck surrounding the pool, that are capable of supporting people sitting on, standing on and diving into the pool, and that allow unencumbered, safe human ingress and egress to and from the pool. The deck lid structures also must allow repair access to the pool cover machinery housed in the trough. Skilled pool designers also recognize that pool wide slots/openings that accommodate the extending and retracting components of pool covers traveling crossing back and forth across the pool from below deck housing troughs detract from pool aesthetics, and present tripping hazards to swimmers accessing and exiting the pool. Accordingly, pool designs have evolved that integrate the leading edge structure carrying the front of the pool cover back and forth over the pool, with the trough housing pool walls, and the trough housing deck lid where the leading edge structure of the pool cover system essentially covers, and/or conceals the pool wide slots/openings when the pool cover is fully retracted. [See U.S. Pat. No. 6,886,188, Epple et al.]
Below-deck troughs housing pool cover systems necessarily encumber accessing and exiting vanishing edge pools. To explain, infinite or vanishing edge pools typically present a below-deck or lowered poolside that allows pool water to flow over into a capturing outside wall gutter below line-of-sight from the opposite side of the pool. Accordingly, the lowered pool edge seemingly extends infinitely or vanishes into the landscape, especially waterscape backgrounds. The housing trough for a pool cover system must be installed adjacent one of the remaining pool walls s affecting access and exit to and from the pool via the remaining pool walls.
Typical housing trough, deck lid structures include braces secured to structural back walls of the housing troughs with support arms cantilevered across the troughs for supporting modular lid plates/trays that in turn integrate, in appearance, with deck top and coping surfaces on, and topping the pool walls. The pool cover deploys to and from the housing trough via the pool wide openings or slots through the pool wall below the deck lid and above a lowered bond beam topping the pool wall between the pool and housing trough. Repair access to the housing trough is accomplished by lifting the modular lid plates/trays off pairs off the supporting cantilever support arms. [See U.S. Pat. Nos. 7,318,243 & 7,011,782, Smith; U.S. Pat. Nos. 6,886,188, & 6,769,141 Epple et al; and U.S. Pat. Nos. 6,862,756 & 6,446,276, Mathis.]
Another approach described in U.S. Patent Application No. 2006/0059614, Bouiss, (2006), provides repair access by rotating a housing trough lid to a vertical position supported on a longitudinal axle spanning the length of the trough supported at the ends by the housing trough walls and medially by one or more axle supports standing on the trough bottom. A plurality of spar ribs perpendicularly extend from the longitudinal axle that in turn support one or more longitudinal deck lid plates that span across the length and width of the housing trough.
In either case, the free, extending ends of cantilever support arms/spars, whether supported by an axle, or structurally secured at the back wall of housing troughs, tend bend or flex downward, responsive to load (weight) supported. In particular, the weight of modular deck lid structures and any people standing/sitting on any modular deck-lid, cause supporting pair(s) of cantilever braces/spars to bend/flex downward. In short, cantilever arm braces/spars alone are ‘springy’, and do not provide static (unmoving or static) support to deck-lid structures covering below-deck troughs housing pool covers systems adjacent sidewalls of swimming pools.
An approach attempting to provide static support to cantilevered structures extending over below-deck troughs housing pool cover systems along sidewalls of swimming pools is described in UK Patent GB 2370760 B, Jeffery et al, issued 26 May 2004, that teaches supporting distal flat or planiform poolside ends of a plurality cantilever structures extending across a housing trough with a vertically translatable, longitudinal I-beam, hydraulically raised or jacked-up, adjacent the wall between the trough and the pool. In Jeffery, the pool cover is clamped between the flat extending cantilevered planiform poolside ends of the deck-lid structure and the top surface of the longitudinal beam structure when it is hydraulically raised to the support position. Jeffery et al also proposes water saving membrane secured between the top of the upwardly translating beam and the wall top between the housing trough and pool for containing water pool, i.e., to prevent pool water from splashing into the housing trough when the cover is fully retracted, wound up in the housing trough. In Jeffery, the cantilever structures are joined with the surrounding deck of the pool.
The Jeffery solution presents more problems than it solves. First the beam raised by the hydraulic jacks must squarely engage simultaneously across the entire length of the poolside planiform structures cantilevered over the housing trough to preclude risk of fracture of the overlying deck. Also, objects/debris on top of the pool cover trapped in the entry slot to the trough housing between the rising support beam and one or more of the cantilevered structures precludes square engagement again creating a risk of fracture of the overlying deck and coping elements above the trapped debris. Next, the cantilevered structure and the supported pool deck also must be sufficiently rigid to support the pool deck without the raised beam, yet have sufficient flexibility and strength to allow for loading of the rising beam at its end points without risk of fracturing the overlying pool deck at the junctures of the pool deck and coping elements cantilevered over the pool cover housing. Third, the scheme does not fail safe, i.e., static support under the structures cantilevered over the trough housing fails upon loss of hydraulic support in one or more of the supporting jacks.
Finally, Applicant in his U.S. Pat. No. 6,938,415 issued Sep. 6, 2005 and U.S. Pat. No. 7,204,291 issued Apr. 17, 2007 respectively describe hydraulic/pneumatic actuation systems, and hydraulically actuated modular lid structures for covering housing troughs located below bottom pool surfaces housing buoyant-slat pool cover systems. In U.S. Pat. No. 6,938,415, the Applicant describes a hydraulic/pneumatic actuation system having a forward/extension cycle for sequentially opening a pool bottom lid covering the housing trough below the pool bottom, then resisting/driving rotation of a cover drum unwinding a buoyant-slat cover from the housing trough to cover a pool, and shutting off. In the reverse or retraction cycle, the hydraulic/pneumatic actuation system sequentially drives rotation of a cover drum in the pool bottom trough retracting the buoyant-slat cover from the pool surface completely winding it up around the cover drum, then allows the pool bottom trough lid to close responsive to gravity that shuts the system off upon lid closure. In U.S. Pat. No. 7,204,291 the Applicant describes a modular pool bottom lid structure for covering a housing trough below the pool bottom adapted to be opened and closed by hydraulically actuated systems.